Propane dehydrogenation reaction is a process of producing propylene by removing some hydrogen atoms from propane through a chemical reaction. The reaction of dehydrogenation of propane to propylene produces olefins, which are more reactive than alkane feedstocks and easily form coke, at high temperatures used for dehydrogenation. This process is based on an endothermic reaction (ΔH0298=+124 kJ/mole), and produces methane, ethane, ethylene, and the like through side reactions.
Of these, ethylene has recently shown an increasing demand in the chemical raw material market. In the past, ethylene was produced chiefly as a by-product of an olefin preparation process, particularly a propylene preparation process. An existing propane dehydrogenation process is a process that removes by-products (methane, ethane, and ethylene) via a de-ethanizer configured to separate C2 and compounds lighter than C2 after propane dehydrogenation reaction, separates the final product propylene from unreacted propane via a propane/propylene splitter, and recycles the unreacted propane for the reaction. In this case, the by-products (methane, ethane, and ethylene) which are separated in the de-ethanizer are recycled as fuel for a heating furnace. However, using valuable ethylene only as fuel is a great economic loss. Furthermore, this supply system alone cannot meet the current demand for ethylene.